Curtain hook



FIG. 1 is a perspective view of a curtain hook showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines shown in the figures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a curtain hook, as shown and described. 